1. Field of the Invention
The invention relates to a device for magnifying visual media and more particularly relates to a device for magnifying visual media that is collapsible when not in use.
2. Description of Related Art
Devices to optically magnify objects have been around for a long time. For example, in 1885, a quartz convex lens was found in the ruins of the palace of King Sennacherib of Assyria (705-681 B.C.). Aristophanes alluded to a xe2x80x9cburning glassxe2x80x9d in his comic play The Clouds (424 B.C.). The historian Pliny (23-79 A.D.) mentions that the Romans also had xe2x80x9cburning-glassesxe2x80x9d. The Roman philosopher Seneca (3 B.C.-65 A.D.) describes that a water-filled glass globe would magnify objects.
Lenses can produce two different types of images: real and virtual. Real images are produced when light from a distant source passes through a converging lens. If the light source is beyond the focal point of the lens on a first side of the lens, the lens will produce a real image at the focal point of the lens on the side of the lens opposite the first side.
A virtual image is produced when an object is placed inside the focal length of a convex lens and viewed through the lens. The location of the virtual image is given by the equation:
1/pxe2x88x921/q=1/f
where p is the distance of the object from the lens, q is the apparent distance of the image from the lens and f is the focal length of the lens. The magnification of the image that appears to be located at q is equal to q/p. So, for example, if the lens has a focal length of 3 cm and the object is placed 2 cm from the lens, the object will appear to be located 6 cm from the lens. In addition, the object will appear to be 3 times larger than it really is.
It is often useful to carry maps for reference in many activities. For example, skiers often carry maps to show the layout of the ski runs at ski resorts. These maps are typically made of paper and folded. To use the map, the skier must remove the map from a pocket, unfold it and attempt to read the map. Often, this is done under inclement conditions such as wind, snow or sleet. As a result, the map often becomes wet or otherwise physically disrupted making it difficult to read and susceptible to destruction.
Further, reading the map is often hampered by the usual practice of the skier wearing ski gloves so that the skier""s manual dexterity is compromised. In addition, unfolding and refolding the map is often a cumbersome process. In view of the foregoing, it is often very difficult to read the map under conditions where the skier usually needs to read the map.
Devices exist for storing maps and the like on a user""s arm, particularly a skier""s arm. Examples of such devices are disclosed in U.S. Pat. Nos. xe2x80x9c4,415,106 issued to Michael J. Connell and Ronald L. Swanson on Nov. 15, 1983 entitled xe2x80x9cMap Holderxe2x80x9d, U.S. Pat. No. 4,957,310 issued to Michael R. Bissonnette on Sep. 18, 1990 entitled xe2x80x9cDetachable Ski of Terrain Mapxe2x80x9d, U.S. Pat. No. 5,400,936 issued to Richard M. Jones and Lynda W. Jones on Mar. 28, 1995 entitled xe2x80x9cArm Band Map Holderxe2x80x9d and U.S. Pat. No. 5,477,633 issued to David C. Leinberger on Dec. 26, 1995 entitled xe2x80x9cDocument Holder for Wearer""s Limbxe2x80x9d. However, in these devices, there are no means for optically enlarging the map or portion of the map that the user will view.
At least one device has been created to address this deficiency, at least in part. In U.S. Pat. No. 5,183,193 issued to Bernie Brandell on Feb. 2, 1993, entitled xe2x80x9cWrist Mounted Map Holderxe2x80x9d, a magnifying glass is attached to the user""s arm by a flexible arm for viewing the map attached to the user""s arm. However, the magnifying glass/arm assembly is cumbersome and is not compact.
The invention comprises an apparatus and a method for magnifying visual media such as a map. The apparatus has three main elements: a lens having a focal length, a visual media positioning assembly and a collapsible positioning assembly for positioning the lens with respect to the visual media positioning assembly.
The lens provides optical interaction with a piece of visual media. This optical interaction is preferably magnification. The visual media assembly positions and protects a piece of visual media. The collapsible positioning assembly positions the lens a distance above the visual media so that the visual media is located closer to the lens than the lens"" focal length. As a result, a magnified virtual image of the visual media is created. The collapsible positioning assembly cooperates with the lens and the visual media positioning assembly so that the entire combination of the lens, visual media positioning assembly and collapsible positioning assembly is substantially flat in its collapsed configuration and positions the lens at a predetermined position above the visual media when in its open or useable configuration.
In the preferred embodiment, because the apparatus is substantially flat when collapsed, the apparatus may be easily carried as for example in a pocket or in a wallet. Alternately, the apparatus may also include a strap or other means for attaching the entire apparatus to a user""s appendage such as an arm. The other means for attaching may include, but not be limited to, an appendage encircling band or strap to which the apparatus is attached. The means for attaching may also take the form of a string having opposed ends, one end attached to the apparatus and the other end attached to the user.
It is a primary object of the invention to provide a means for viewing visual media that allows the visual media to be magnified.
It is another object of the invention to provide a means for magnifying visual media that is substantially collapsible.
It is another object of the invention to provide a means for magnifying visual media that is conveniently carried and stored.
In one form of the invention, it is an object of the invention to provide a means for magnifying visual media that, in a collapsed configuration, substantially has the size and thickness about of a credit, business or playing card.
In one form of the invention, it is an object of the invention to provide a means for storing and magnifying a visual media that is attachable to the user.
These and other objects of the invention will be clear from the description of the invention given herein. Throughout the description, like reference numbers, wherever referred to and unless specifically stated otherwise, refer to like elements.